"But to be effective, Green said a patient would have to smoke an unrealistic amount of marijuana."

"If you want to maintain a low interocular pressure with marijuana, then you have to smoke a joint every 1 to 2 hours which is 10 to 12 joints a day, which is 4,000 a year," he said. "That's by anybody's definition -- no matter how liberal you are -- a considerable consumption."

"His study is published in the recent issue of the American Medical Association's journal, Opthamology."